1. Field of the Invention
The present invention relates generally to a delivery system for dietary fibers and more particularly to a delivery system for soluble dietary fiber supplements preferably in the form of a safe, chewable tablet, lozenge, wafer, cookie or the like which is comprised in part of a relatively low viscosity, non-gelling and organoleptically pleasing dietary fiber component.
2. Description of the Prior Art
Unlike other nutrients, dietary fiber is not a single substance, but is a term used to identify plant polysaccharides and lignins that are not hydrolyzed by the endogenous secretions of the human digestive system. Thus, they reach the colon intact. Plant components which make up dietary fiber include, among others: structural polysaccharides (cellulose and hemicellulose), nonstructural polysaccharides (pectines, B-glucans; gums and mucilages) and structural non-polysaccharides (lignin). Dietary fibers are commonly characterized by their water solubility and their relative susceptibility to microbial degradation into fermentable and nonfermentable fiber fractions. In general, pectines, gums and mucilages are water soluble, while lignin, cellulose and hemicellulose are water insoluble.
Dietary fibers by definition reach the colon intact and thus generally escape digestion and absorption in the small intestines; however, such fibers are susceptible to varying degrees of microbial fermentation or degradation in the colon. Such degradation results in the production of carbon dioxide, hydrogen, methane, and various short chain fatty acids.
For much of the twentieth century the common notion among clinicians and nutritionists was that fiber was roughage or the like comprised of indigestible cell walls. Except for providing bulk for normal bowel function, such fiber was considered to be of no nutritional value. Accordingly, many food scientists directed their efforts toward enhancing the purity of food by removing dietary fiber.
However, during the last few decades, stimulated principally by epidemiological observations revealing differences in disease patterns between populations, researchers began to accumulated a large body of evidence linking a low fiber western diet with the incidence of numerous chronic diseases. Numerous laboratory and clinical investigations have also confirmed various risk factors associated with low fiber diets and the protective nature of high fiber diets.
The association of high dietary fiber intake with lower risk or improvement in several chronic diseases has led to recommendations to increase dietary fiber consumption to 20–35 grams per day. Because of these recommendations and the mounting recognition of health benefits of high fiber diets, health care professionals have aggressively attempted to encourage individuals to consume high fiber diets that are rich in fruits, vegetables, legumes and whole grains. Regrettably, many of the most popular foods, and particularly those most popular in western diets, are low in dietary fiber. Thus, for those consuming an affluent “refined western diet”, satisfying these recommendations is a difficult task. Accordingly, despite the recommendations advocating high fiber diets, the intake of dietary fiber has not significantly increased. Recent consumption surveys reveal that average dietary intake of fiber remains at approximately 10–12 grams per day.
As a result, a variety of dietary fiber supplements have been marketed for increasing the consumption of dietary fiber. Unfortunately, however, such supplements have achieved limited consumer acceptance. Much of the dissatisfaction arises because of the physical organoleptic and other characteristics of the fiber components which make up the great majority of dietary fiber supplements currently available. Common dietary fiber supplements are comprised of fiber components such as psyllium (sold under the trademark Metamucil or Fiberall), methylcellulose (sold under the trademark Citrucel) and polycarbophil or calcium polycarbophil (sold under the trademark Fiber Con). These generally have a significant affinity for water. Thus, when exposed to water or other fluids prior to or during ingestion, or when progressing through the digestive system, these components tend to swell quickly and produce highly viscous fluids and gels. For instance, when hydrated, psyllium fiber produces an unacceptably gummy, chewy product. This has led directly to increased safety risk such as choking, obstruction and the like, both during and after ingestion. In fact, scientific literature has reported obstructions (esophageal and small bowel) requiring medical attention from the consumption of both insoluble and soluble fiber supplements.
To minimize this problem, it is recommended that present fiber supplements be ingested while consuming a large quantity of liquids (a minimum of eight ounces of fluid) or that smaller quantities of the supplement be ingested. In fact, the FDA's Tentative Final Monograph for Laxatives specifies that a full glass (8 ounces) of liquid be taken with each dose of certain fiber supplements. Typically, dietary fiber supplements are ingested in the form of swallowable tablets, reconstitutable powders or wafers. Swallowable tablets, because of the above safety concerns, are limited to tablets of one gram or less and more typically 0.5 grams or less. This, however, leads to two areas of consumer dissatisfaction: the need to ingest a large amount of liquid per dose as well the need for a large number of doses to get a meaningful amount of fiber.
Fiber supplements in the form of a reconstitutable powder have also met with limited consumer acceptance due principally to mouth feel of the product (the texture and grittiness), gelling due to viscosity buildup, visual appearance, the relatively large amounts of liquid required for mixing and consumption and limited palatability. The inconvenience of reconstituting and ingesting the product outside the home and the necessity for cleanup also encumbers lifestyle and results in poor compliance. As an alternative, fibers supplements are often offered as wafers or as swallowable tablets as described above.
To overcome some of the problems identified above, the prior art teaches the encapsulation or pre-coating of dietary fiber supplements delivered as swallowable tablets. Although this somewhat improves certain of the organoleptic properties by masking undesirable flavors and texture and delays hydration until it passes through the oral cavity, the limitations resulting from the relatively small swallowable tablets continue to exist. The prior art also describes attempts to mask the fibrous mouth feel of current fiber supplements by concealing the dietary fiber in wafers, baked goods, granola-type products, power bars, cookies, cereals and snack foods. While this technology has achieved some degree of success, it often requires the inclusion of ingredients high in fat, carbohydrates and calories and low in dietary fiber. Thus, consumers wishing to restrict their caloric intake are often reluctant to utilize such products. Further, the level of dietary fiber that can be incorporated into other foods without adversely affecting the taste and mouth feel is quite limited. In general, the upper limit is about 5% by weight.
Still further, the prior art teaches the use of fine powders of dietary fibers, excipient and or dispersing agents to reduce the formation of fibrous clumps or “fish eyes” during rehydration. In comparison to coarser powders, the fine powders of dietary fibers tend to be less gritty upon reconstitution.
According, there is a need for a dietary fiber supplement which addresses the problems in the prior art and provides a dietary fiber supplement and a delivery system for a dietary fiber which does not pose safety concerns resulting from viscosity buildup or gelling and which is palatable, aesthetically pleasing and exhibits characteristics which enable it to be delivered as a chewable tablet or lozenge without the choking, obstruction or other safety concerns.